1. Technical Field
The present invention relates to high-voltage alternating current (AC) light-emitting diode (LED) structures, and more particularly, to a high-voltage AC LED structure for use in illumination.
2. Description of Related Art
U.S. Pat. No. 6,853,011 has disclosed a light emitting epi-layer structure containing a temporary substrate of absorption light type on one side, while the other side thereof is then adhered to a transparent substrate of light absorption free by benzocyclobutene (BCB) bonding layer. After that, the light absorption temporary substrate portion is removed. The resulted light emitting structure is then patterned to form a connection channel to connect the first ohmic contact electrode and form an isolation trench to separate the active layer of the light emitting structure into two parts. Thereafter, a second ohmic contact electrode on the cladding layer and a bonding metal layer filled in the first channel and on second ohmic contact electrode are successively formed. The resulted LED structure is hence convenient for flip-chip package structure since two bonding metal layers have the same altitude.
U.S. Pat. No. 6,998,642 has disclosed a semiconductor structure with two light emitting diodes in series connection. The semiconductor structure comprises two light emitting diodes (LEDs) having the same stack layers and abutting each other but spaced by an isolation trench. The stack layers from a bottom thereof include a thermal conductive substrate, an nonconductive protective layer, a metal adhering layer, a mirror protective layer, a p-type ohmic contact epi-layer, a upper cladding layer, an active layer, and a lower cladding layer. Two p-type ohmic contact metal electrodes for two LEDs are formed on an interface between the mirror protective layer and the ohmic contact epi-layer and buried in the mirror protective layer.
Although the LED structure of U.S. Pat. No. 6,853,011 is applicable to flip-chip package structures, not only is the connection between the two light emitting diodes impossible to be accomplished in the absence of a submount, but the flip-chip process entails processing multiple chips and therefore adds to the complexity of the process. Although U.S. Pat. No. 6,998,642 is effective in electrically connecting two light emitting diodes, metal-based bonding can only be performed by a complicated process to thereby compromise production performance and incur costs.
Light-emitting diodes are manufactured mostly by a non-wafer-level process according to the aforesaid prior art without taking account of users' need for coupling multiple light-emitting diodes together by series connection, parallel connection, or parallel-series connection. Accordingly, it is imperative to manufacture a high-voltage alternating current (AC) light-emitting diode simply and conveniently.